A 14-h night-shift in the control room of a fire brigade

All 29 operators in the control room of a fire brigade performed test sessions during work and leisure time at 2-h intervals on a day with a 14-h night-shift, a day off and a day with a 10-h morning shift. The test sessions consisted of a visual search choice reaction time test and two Sternberg memory search tests (1 or 5 letters had to be memorized). Furthermore, the operators recorded their oral temperature and their subjective alertness before each test session. The subject also kept a diary of work and sleep times for 14 days. The circadian rhythm of body temperature was hardly changed by a single night-shift. Parallel to the body temperature, the subjective alertness fell significantly during the night-shift reaching a minimum value at 06:00 h. The mean reaction times increased non-significantly at the end of the night-shift and the results of the two Sternberg memory search tests showed no significant trends. The sleep of the operators after the night-shift was on average reduced to 5 hs 34 min. The results of subjective rating of alertness and reaction time test are interpreted as effects of the combined influences of circadian rhythmicity, sleep loss and time on professional task. Most results support the conclusion that a 14-h night-shift without extensive breaks is not acceptable.     

Interval estimation for log-linear models with one variable subject to non-ignorable non-response

Summary.  Log-linear models for multiway contingency tables where one variable is subject to non-ignorable non-response will often yield boundary solutions, with the probability of non-respondents being classified in some cells of the table estimated as 0. The paper considers the effect of this non-standard behaviour on two methods of interval estimation based on the distribution of the maximum likelihood estimator. The first method relies on the estimator being approximately normally distributed with variance equal to the inverse of the information matrix. It is shown that the information matrix is singular for boundary solutions, but intervals can be calculated after a simple transformation. For the second method, based on the bootstrap, asymptotic results suggest that the coverage properties may be poor for boundary solutions. Both methods are compared with profile likelihood intervals in a simulation study based on data from the British General Election Panel Study. The results of this study indicate that all three methods perform poorly for a parameter of the non-response model, whereas they all perform well for a parameter of the margin model, irrespective of whether or not there is a boundary solution.     

'Dealing With It': Experiences of Young Fathers in and Leaving Care

The interface between two major UK Government priorities—reducingunwanted teenage pregnancies and supporting teenage parents,and improving the health and well-being of young people in andleaving local authority care—has been the focus of recentresearch. The overall aims of this study were to explore factorscontributing to early pregnancy and parenthood among young peoplein and leaving local authority care; to determine the kindsof support available to these young people; and to identifywhat enables or prevents the delivery of the support they need.Via in-depth interviews, and in four contrasting geographicalareas, data were collected from young people and service providersacross England. This paper analyses data of relevance to theexperience of young fathers who have been looked after—toconsider how the needs of these young men might be better addressedthrough policy and practice. In-depth interviews conducted withyoung fathers and service providers highlighted three key aspectsof their experience that must be addressed if future needs areto be better provided for. These are: social exclusion, trustand more flexible forms of service provision. The implicationsof these issues for future policy and programme developmentare discussed.     

Modelling spatially correlated data via mixtures: a Bayesian approach

Summary. The paper develops mixture models for spatially indexed data. We confine attention to the case of finite, typically irregular, patterns of points or regions with prescribed spatial relationships, and to problems where it is only the weights in the mixture that vary from one location to another. Our specific focus is on Poisson-distributed data, and applications in disease mapping. We work in a Bayesian framework, with the Poisson parameters drawn from gamma priors, and an unknown number of components. We propose two alternative models for spatially dependent weights, based on transformations of autoregressive Gaussian processes: in one (the logistic normal model), the mixture component labels are exchangeable; in the other (the grouped continuous model), they are ordered. Reversible jump Markov chain Monte Carlo algorithms for posterior inference are developed. Finally, the performances of both of these formulations are examined on synthetic data and real data on mortality from a rare disease.     

Ancestral Inference in Population Genetics Models with Selection (with Discussion)

A new algorithm is presented for exact simulation from the conditional distribution of the genealogical history of a sample, given the composition of the sample, for population genetics models with general diploid selection. The method applies to the usual diffusion approximation of evolution at a single locus, in a randomly mating population of constant size, for mutation models in which the distribution of the type of a mutant does not depend on the type of the progenitor allele; this includes any model with only two alleles. The new method is applied to ancestral inference for the two‐allele case, both with genic selection and heterozygote advantage and disadvantage, where one of the alleles is assumed to have resulted from a unique mutation event. The paper describes how the method could be used for inference when data are also available at neutral markers linked to the locus under selection. It also informally describes and constructs the non‐neutral Fleming–Viot measure‐valued diffusion.     

中韩日三国未来在经济上的竞争与合作

一、导言(一)改变中的世界经济数千年前,古代中国在比较厚实的基础之上,就已发展出灿烂的文化,而这先进的文化与经济也通过“丝绸之路”向西方传播。     

A Content Analysis of Violence in American War Movies

In a content analysis of movie violence, we randomly selected twelve top-grossing American war films from four decades (1970 to 2002). We coded for implements of violence, length of violence, gore, and violence directed at noncombatants. We hypothesized that recently released war movies would be more violent than those released earlier. We found that films released since 1990 did contain more violence compared to others. Further, the intensity of gore increased in recently released movies.     

When Strategic Approaches get Stuck: Maps out of the Mire

Using a biopsychosocial model, a three dimensional map provides guidelines for changing from strategic therapy when progress in this approach falters. The method is pragmatic and atheoretical, and brings together ideas from various schools which empirically have been found useful. Practical and inclusive guidelines are offered for family (and individual) therapy which address two important issues: reinforcement of change when progress is occurring, and a shift from an interactional to another dimension when stuck points are reached. The multi-dimensional approach is clear, can be used by individuals or teams, lends itself to teaching and is of particular value for entrenched and complex problems. Four case histories are presented to highlight the approach.